Heavy metal polluted soils can be remediated using plants, a process called phytoremediation. However, high concentrations of heavy metals can negatively affect plant physiology and growth. We experimentally evaluated the effects of cadmium (Cd) on the growth, (i.e. height, shoot and biomass) and physiology (i.e. leaf chlorophyll and relative water contents) of Tamarix usneoides. In a greenhouse experiment, T. usneoides clones were subjected to a once off treatment of 100 mmol/l NaCl with three different Cd concentrations (6, 12, and 18 mg/kg) applied 3 times/week for eight weeks. We predicted that plant health would decrease with an increase in Cd concentration. Results revealed a 35.9% reduction in chlorophyll content between the 18 mg/kg Cd treated plants and the control, suggesting that T. usneoides experienced a reduction in photosynthetic rate, which in turn influenced the growth and relative water content (RWC) of the plant. Although T. usneoides’ growth and physiology were significantly decreased at 12 and 18 mg/kg Cd concentrations, the plants tolerated up to 6 mg/kg Cd concentration, a level found in most anthropogenic Cd-contaminated soils. Tamarix usneoides should thus be confirmed as a good phytoremediation candidate once its ability to extract, translocate and concentrate Cd has been determined.
Temminck's pangolin (Smutsia temminckii) is a threatened mammal found in southern and eastern Africa. It is the most widely distributed African pangolin species yet is listed as Vulnerable on the IUCN Red List due to a projected population decline of 30%–40% within the next three generations. This species' secretive, predominantly nocturnal behaviour and generally low population densities make it difficult to directly assess its distribution, and thus, alternative methods are required. Furthermore, many historical and some contemporary records of this species exist from outside of its accepted range, suggesting that the distribution may be greater than currently accepted, although the validity of these records has never been assessed. We used MaxEnt modelling to evaluate the most likely distribution of S. temminckii in South Africa and compared the past and present distribution of the species, as well as assessed the probable validity of the questionable records. Our results suggest that one of the questionable historical museum records is probably valid, while the other may refer to an erroneous collecting locality. At least some contemporary sightings which were originally deemed questionable are probably valid, while others should be treated as dubious until supporting information to validate their authenticity becomes available.